Submission #1262422

#	Time	Username	Problem	Language	Result	Execution time	Memory
1262422		LeonidCuk	Dynamic Diameter (CEOI19_diameter)	C++20	24 / 100	5094 ms	10436 KiB

diameter

#include <bits/stdc++.h>
using namespace std;
vector<vector<pair<int,long long>>>g;
long long res;
long long dfs(int a,int b)
{
    long long nmax1=0,nmax2=0;
    for(auto i:g[a])
    {
        if(i.first!=b)
        {
            long long t=i.second+dfs(i.first,a);
            if(t>nmax1)
            {
                nmax2=nmax1;
                nmax1=t;
            }
            else if(t>nmax2)nmax2=t;
        }
    }
    res=max(nmax1+nmax2,res);
    return nmax1;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    long long n,q,w,a,b,c,last=0;
    cin>>n>>q>>w;
    g.resize(n+1);
    vector<pair<int,pair<int,long long>>>v;
    for(int i=0;i<n-1;i++)
    {
        cin>>a>>b>>c;
        v.push_back({a,{b,c}});
        g[a].push_back({b,c});
        g[b].push_back({a,c});
    }
    for(int i=0;i<q;i++)
    {
        cin>>a>>b;
        a=(a+last)%(n-1);
        b=(b+last)%w;
        int a1=v[a].first,b1=v[a].second.first;
        for(int j=0;j<g[a1].size();j++)
        {
            if(g[a1][j].first==b1)g[a1][j].second=b;
        }
        for(int j=0;j<g[b1].size();j++)
        {
            if(g[b1][j].first==a1)g[b1][j].second=b;
        }
        res=0;
        dfs(1,1);
        last=res;
        cout<<last<<"\n";
    }
}

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 0 / 7
• Subtask 4: 0 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 27